Apparatus for making electrical condensers



y 1930 c. E. VAWTER 1,757,692

APPARATUS FOR MAKING ELECTRICAL CONDENSERS Filed July 1924 Q 2 Sheets-Sheet 1 ATTORNEY y 1930- c. E. VAWTER 1,757,692

APPARATUS FOR MAKING ELECTRICAL CONDENSERS Filed July 1, 1924' 2 Sheets-Sheet '2 INVENTOR mil-M.

ATTORNEY Patented May 6, 1930.

UNITED STATES CHARLES E. VAWTER, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR '10 DUBILIER PATENT OFFICE CONDENSER CORPORATION, OF NEW YORK, N. Y., A CORPORATION OF DELAWARE APPARATUSIOR MAKING ELECTRICAL CONDENSERS Application-filed July 1 1924. Serial No. 723,601.

where low fixed values of capacity are desired. The condensers are made up of a plurality of alternately disposed layers of electrically conducting material and suitable dielectric material. Alternate conducting layersare connected together to form one termi-.

nal of the condenser and the remaining conducting layers are interconnected to form the otherterminal of the condenser, the strips of .dielectric material interposed between the conducting layers serving to insulate the layers from each other and effect a suitable spacing of the layers. The capacity of the condenser is dependent upon the number of plateswhich it contains, each pair of adjacent plates with theinterposed sheet .of dielectnc material constituting atwo plate unit. The total capacity of the condenser is the sum of the capacities of these individual two plate units connected in parallel, that is, a three .plate condenser has twice the capacity of a two plate condenser having like plates and,

dielectric, a four plate condenser has three times the capacity of a two plate condenser, and so on. I

It is a principal object of this invention to provide a method and apparatus for making condensers of this type on a commercial scale by means of which condensers of good electrical qualities and of rugged mechanical construction may be roduced at an extremely low cost of manu acture. The condenser is made by assembling within an integral metal casing a plurality of the alternately 'arranged layers of electrically conducting material and dielectric material after which the casing is squashed down upon these elements by means of a blow under a suitable die. It is important that the conducting plates and strips of dielectric constituting the condenser be held firmly within the casing in closely adjacent relation. If the condenser elements are not held together firmly and evenly they will tend to vlbrate during operation and.

such vibration causes slight variations in the capacity of the condenser which both produces undesirable noises in the reproducing elements of the set and causes distortion of the wave form of the varying current traversing the condenser with the result that the reproduced sounds will be distorted. The condenser casing is deformed upon the plates of the condenser preferably by means of a single blow under a punch press. 7

In order to insure that the condenser elements will be held firmly and evenly throughout their length in the finished condenser, an accurate regulation of the force of the deforming blow is required. Too light a blow fails to deform the casing sufficiently to securely grip the condenser elements. heavy a blow flattens the condenser out completely and the slight recoil of the metal of the casing after the blow is delivered leaves the case outwardly convex along its middle line with the result that the condenser plates are not held firmly. To obviate, these difficulties, the casing is deformed upon the condenser platesin such conformation that the plates are engaged by a convex inner surface of the casing. The casing is preferably shaped to present two opposing inner convex surfaces between which the'condenser plates are, assembled. The casing is then subjected to a blow between the flat faces of suitable ture to grip the condenser elements along their median lines and prevent recoil of the casing along this line which would result in looseness of the elements at that point.

For accomplishing regulation of the deforming blow to e ect deformation of the casing in the fashion just described, the support upon which the condenser 'is placed at i the like.

the time it is subjected to' the deforming blow is carried .by a resilient mounting}, such as may be obtained for instance by a eavy coil spring of considerable length. The spring is adjusted to a certain degree of compression so that a predetermined force of blow is required to depress the support. At each blow of the deforming die the resiliently mounted support will therefore be slightly depressed and for the reason that the force of the blow is taken up by the resilient mounting, successive condensers will be subjected to blows of equal violence. The spring or similar resilient mounting may be adjusted to such compression that the proper force of blow will be applied to each condenser.

Mica is the best dielectric material for condensers of this type. Layers of mica suitable for dielectric material in these condensers are, however, apt to be shattered when subjectedto a violent blow, and it is therefore necessary to carefully restrict the violence of the blow to such degree that the mica sheets will not be damaged. The resilient mounting of the support upon which the condenser.

is placed satisfactorily limits the force of the blow and causes each blow to be uniform with the result that no difficulty due to shattering of the mica sheets is encountered. The force of the blows is uniform notwithstanding slight variations in thickness of the condenser due, for instance, to inequalities in the thicknem of the mica sheet-s employed, or This is truev because the spring support furnishing the resilient mounting may be depressed a certain amount with substantially no change in the force required to overcome the compression of the spring. This result is efiected by making the spring long with respect to the variations in the amount which the spring is depressed at each blow. With this arrangement, it is even possible to insert one or two additional condenser elements without substantially changing the force of the blow, although thecondenser thickness is thereby varied considerably. It' will be understood however, that when a different number of condenser plates are used, it is ordinarily advisable to adjust the sprin accordingly, so that a proper blow is o tained. The resilient mounting, however, amply compensates for all such variations as occur during an ordinary manufacturing run due to variations in thickness, and the like, of the various parts of the condenser. By this means each condenser is formed at a single blow and the process of manufacture is correspondingly rapid. By regulating for a uniform forceof blow, the advantages of a slowly applied pressure, such as for instance a hydraulic press, are obtained and at the same time rapidity of manufacture is attained. a

It is also 'an-object of the invention to provide a convenient means for ready assembly and alignment of the condenser plates and strips of dielectric material in the casing. The electrically conducting plates or laminations must of course be narrower than the dielectric strips and must be properly positioned both laterally and longitudinally with respect to the casing and to the dielectric strips. This invention contemplates an effective assembling and aligning means by which the various condenser elements may be rapidly assembled in proper relative position previous to .being subjected to the deforming blow which secures the elements in the casing.

It is a still further object to provide a convenient set of terminals on the condenser for incorporation into an electrical circuit, this feature being provided without necessitating any operation additional to those which would otherwise have to be employed in the manufacture of the condenser.

I have illustrated a preferred embodiment of my invention in the accompanying drawings in which Figs. 1 and 2 are views illustrating the manner of shaping the condenser casing prior to the assembly of'the condenser elements in the casing; Figures 3 and 4 are a transverse sectional view and a plan view respectively showing the condenser elements assembled in the casing; Figures 5 to 8 inclusive illustrate the apparatus employed for properly positioning the various elements of thecondenser within the casing; Figure 9 is a new showing the apparatus employed for securing the condenser elements in the caslng; Figures 10 and 11 are a transverse sectlona-l view and a plan view respectively of the completed condenser; Figure 12 illustrates the shape of one of the electrically conducting plates of the condenser; and Fi ures 13 and 14 are views illustrating a mod fied form of plate.

The material of the condenser casing is an appropriate metal, for instance brass, whic is possessed of a considerable degree of hardness and yet which can be flexed and deformed without rupture. The casing 1 into which the condenser elements are assembled is of elon-' gated cross section presenting convex inner surfaces for the purpose of engaging the condenser elements along the middle of their width. The elongated casing 1 may be formed from cylindrical tubing either by drawing or by stamping. Round tubing may conveniently be cut into exact lengths by means of automatic machinery, and for that 120 reason I prefer to first cut lengths of cylindrical tubing into sections of such size as to constitute the individual condenser casmgs and then by a stamping operation alter 'the cross-section of the tube portions to the' desired conformation. V A length of cylindrical tubing 2 is placed in an apparatus havmg spring pressed side supports 3 and havinga pair of dies 22 presenting op osed convex surfaces for engagement with t e tubing; 1:30v

Upon operation f the. dies as indicated in Figure 2 the cas ng is distorted from a circular cross section to .an elongated section having sides bulged in according to the shaping of the convex surfaces of the dies 22. As the section of tubing is flattened it spreads laterally and the spread is permitted by reaconvex surfaces has been formed, alternately disposed strips 4 of dielectric material and plates 5 of electrically conducting material are assembled and then placed within. the casing. For the purpose of more securely holding the condenser elements in the completed' condenser, one or more strips 6 of oiled linen or similar compressible material 7 is provided immediately adjacent the walls of the condenser casing, after the fashion disclosed in my co-pending application Ser. No. 635,210, filed April 28, 1923. The strips 4 of dielectric material are of width substantially equal to the width of flattened casing 1 so that when the strips are assembled in the casing their contact with the casing sides serves to center them properly. The strips of dielectric material are of the same length as the condenser casing and are assembled to be flush with the ends of the casing in the finished condenser. The strips of linen 6 are of the same width as the dielectric strips 4 and may be of the same length or slightly longer so that they project slightly from-the 7 ends of the casing in the finished condenser condenser.

' 'erly located in the condenser with respect to each other and with respect to the interposed as indicated at 6 in Figure 4.

The electrically conducting strips or plates 5 are considerably narrower than the dielectric strips 4 in order that short circuiting of the plates and leakage between adjacent plates will be prevented. The plates are of generally rectangular shape as indicated particularly .in-Figure 12 and are provided at one end with a projecting tab 7 having a hole 8 punched in it near its end. The tabs 7 of alternate plates project from opposite ends of the condenser, as indicated in Figure 4,

and thus constitute the two terminals of the It is of great importance in order to provide a condenser of proper electrical charac terist cs that the condenser plates 5 be propsheets 40f dielectric material. In order to properly align the plates in a lengthwise direction, the plates, together with the interposed strips of dielectric material, are assembled upon a suitable support 9 (Figs. 5 to 8) having two upwardly projecting pins 10 spaced apart a distance equal to'the desired spacing between the holes 8 in the tabs of the plates 5 projecting at the respective ends of the finished condenser. The plates 5 and the dielectric strips 4 are assembled and placed in the casing 1 and are then placed upon the support 9 withthe pins 10 threaded thru the holes in the tabs 7, as indicated in Figure 8. In this position the condenser casing 1 may be shifted into a central position between the pinslO and at the same time the strips 4 of dielectric material may be adjusted by the operatorto come flush with the ends of the casing 1 by merely tapping the ends of the casing.

For the purpose of properly locating the plates 5 widthwise of the condenser casing 1, adjusting slides 11 are employed. The support 9 is slotted as indicated at 12 to furnish a slidin track for the adjusting member 11 so that t ey may be moved into contactwith the tabs 7 of the condenser plates after the condenser has been placed upon the support 9. The sides of the tabs 7 are tapered as indicated at 13 and the adjusting slides 11 are tapered correspondingly at 14 so that when the slides are moved into contact with the tabs 7 the tapered portion of the slides engages with the tapered portion of the tabs and brings them into proper lateral adjustjusting slides 14 which, by the action of their tapered surfaces against the'tapered surfaces of the tabs 7, serve to adj ust the plates 5 laterally of the condenser casing into exactl .superimposed relation. The adjusting sli cs 11 are recessed as indicated at 16. toafford ample clearance for the ends of the tab 7, the clearance here shown being adequate to accommodate the extended tab provided on the type. of plate shown in Figures 13 and 14.

- In order to properly secure the condenser elements in the casing, it is essential that the deforming ,blow which presses the'condenser easing into contact .with the condenser elements be accurately adjusted. The apparatus for accomplishing this is indicated in Fi re 9 and comprises an upper flat die 17 an a lower flat die 18, which dies cooperate to produce the desired action. The support 9 is placed upon the die 18 and the upper die 17 descends upon thecondenser and deforms the casing 1 into the conformation indicated in Figure 10. It will be noted from Figure 10 that the casing 1 of the completed condenser hasbeen substantially flattened, but

nevertheless retains a sufliclent amount of in the middle being avoided. The linen strips 6 aid in securing uniform pressure over the entire surface of the elements.

The force of blow which will deform the easing into exactly the proper conformation is critical and therefore must be uniform throughout a manufacturing run. To attain such a uniformly regulated force the die 18 is mounted on a spring support 19 so that the force of the blow is taken up by the spring. An adjusting element 20 1s provided to regulate the compression under which the spring 19 is held when the die 18 is in its normal position. The spring is long relative to the movement of the die 18 so that throughout the movement of the die the pressure exerted on it by the spring is substantially constant. In this wayit is possible to produce under a rapidly operating punch press successive blows of uniform force with the result that 20 the condenser casings in a manufacturing run are each deformed to exactly the proper conformation to secure the most effective connection between the casing and the condenser elements and at the same time to avoid blows of excessive force which would shatter the mica constituting the dielectric strips.

In Figures 13 and 14 I have illustrated a modified form of condenser plate. In this modified construction the tab 7 of the plate is extended as indicated at 21 into a portion which projects materially beyond the hole 8 provided 1n the tab. After the condenser casing has been deformed upon the condenser elements, the ends 21 of the condenser plates may be bent up by means of a suitable die,

as indicated in Figure 14, so that a substantially cylindrical or semi-cylindrical trough is provided in which a wire may be laid and conveniently soldered when the condenser is connected into an electrical circuit. Due to the fact that when a plurality of the plates 5 are employed, an eyelet is inserted thru the holes 8 in the tabs 7 of the plates for the urpose of effecting an electrical connection tween the respective plates, the bending up of the ends 21 does not involve an additional operation. The bending dies for accomplishing this operation may be provided on the same apparatus which inserts the eyelet into the holes 8 and the bending operation accomplished at the same operation which introduces the eyelet. Either one plate at each end of the condenser may be provided with the extended tab 21 or all of the plates may be provided with such a tab and bent up to gether and then tinned to eflect a good electrical connection between the respective plates.

I have described a preferred embodiment of my invention which contemplates the provision of apparatus for manufacturing flat plate condensers of the' type referred to in a simple and effective manner at low cost and p which at he sametime produces a product 66 having good electrical and mechanical qualities. Certain changes and modifications may be introduced into the rocess and certain structural changes may e made in the apparatus without departing from the invention as defined in the appended claims.

I claim:

1. Apparatus for making electric condensers of the class described comprising means for supporting the condenser casing with the condenser elements assembled therein, means -for subjecting the condenser casing to a blow to deform said easing into permanent engagement with said elements-along sides of the casing which. are slightly curved, means for regulating the force of said blow to a predetermined value and means for controlling the force of each successive blow to said predetermined value.

2. Apparatus for making electric condensers of the class described comprising means for supporting the condenser casing with the condenser elements assembled therein, means for subjecting the condenser casing to a blow to deform said casing into permanent engagement with said elements, and a resilient mounting for said supportin means yieldable under the force of the blow to thereby prevent damage to the condenser parts.

3. Apparatus for making electric condensers of the. class described comprising means for supporting the condenser casing with the condenser elements assembled therein, means for subjecting the condenser casing to a blow to deform said easing into permanent engagement with said elements, and a resilient mounting forthe condenser support exerting a substantial pressure upon said support to maintain it in normal position and at the same time permit a limited movement of said support without substantially effecting the pressure exerted thereon, whereby said resilient mounting limits the force of the blow to a predetermined value and regulates the force of each blow to said predetermined value. I

4. Apparatus for makin electric condensers of the class described comprising means for supporting the condenser casing with the condenser elements assembled there-- in, means for subjecting the condensercasing to a blow to deform said casing into permanent engagement with said elements, a resilient mounting for the condenser support exerting a substantial pressure upon said support to maintain it in normal position and at the same time permit a limited movement of said support without substantially effecting the pressure exerted thereon, and means for adjusting said resilient mounting to vary the pressure exerted upon said support.

5. Apparatus for making electric condensers of the class described comprising means for supporting the condenser casing with the condenser elements assembled there-' 60 proper in, means for subjecting the condenser casing to a blow to deform said caslng into permanent engagement with said elements, a. spring constituting a yielding mounting for said condenser support and means for regulating the pressure of said spring to thereby control the force of the blow, said spring being of great length relative to the variations in the extent of movement of said support during formation of successive con.- densers .Whereby the forces of successive blows are substantially identical notwithstanding variations in the thickness of the condenser. Y Y

6. Apparatus for making electric condensers of the class described comprising means for deforming the condenser casing to present a convex surface adjacent the condenser elements, means for substantially flattening said casing at a single blow and means for regulating the force of said blow to such value that the substantially flattened casing preserves a slight convex conformation adjacent the condenser elements.

7. Apparatus for making electric condensers of the class described comprising 'a pair of curved dies for deforming the condenser casing to present opposing convex surfaces adjacent the condenser elements, a pair of flat dies for substantially flattening said casing at a single blow, a resilient mounting for one of said fiat dies to thereby limit the force of the blow and regulate successiveblows to a uniform force and adjusting means for altering the yielding strength of saidresilient mounting to thereby control the force of said blows to a predetermined value.

8. Apparatus for making electric condensers of the class described comprising means for supporting the condenser casing with the condenser elements assembled thereand means for properly positioning the condenser plates relative to the other parts of the condenser, said means comprising a member having a tapered recess cooperating with corresponding tapered portions pro-' vided on said plates.

9. Apparatus for maln'ng electric condensers of the class described comprising means for supporting the condenser casing with the strips of dielectric and condenser plates assembled therein, said strips of dielectric being substantially equal in width to the width of said casing, and a member movable along the condenser support having a tapered recess cooperating with corresponding tapered portions provided on the condenser plates, member into contact with said plates affects lateral positioning of said plates.

- 10. Apparatus for making electric condensers of the class described comprising means for-supporting the condenser casing with the strips of dielectric material and the condenser plates assembled therein, said whereby movement of said strips of dielectric material being substantially equal in width to casing, a member movable along the condenser support having a tapered recess cooperating with corresponding tapered portions provided on the condenser plates wheremovement of said member into contact the width of saidcasing, a member movable along said condenser support having a tapered recess cooperating with correspondingly tapered portions provided on the condenser plates, whereby movement of saidmember into contact with said plates eifects proper lateral positioning of said plates,

xed pins uponsaid condenser support fitting into spaced holes provided in the condenser plates to thereby efiect proper lengthwise positioning of said plates, means for deforming the condenser casing upon the condenser elements thus located to present a convex. surface adjacent the condenser elements, means for substantially flattening said casing at a single blow and means for regulating the force of said blow to such value that the substantially flattened casing preserves a slight convex conformation adjacent the condenser elements.

' In testimony whereof I aflix my signature.

CHARLES E. VAWTER.

the width of said. I 

